Timebase error when encoding
Frames Per Second 

The output file format you've chosen, Xvid, does not support the frame rate you've chosen. Your error, 


  Timebase 20999/500000 not supported by MPEG 4 standard, the maximum admitted value for the Timebase denominator is 65535 


basically says: your frame rate (5 frames per second with a framerate base of 0.210, totaling 23.81 fps) isn't compatible with your output file format. 

How to fix 

As far as I'm aware you can't fix it, you have to either change the fps or the output file format. 

Happy Blendering!